title: Variable-ratio pushrim-activated power-assist wheelchair eases wheeling over a variety of terrains for elders.
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D011211:Electric Power Supplies; D004576:Electromyography; D004867:Equipment Design; D006804:Ergonomics; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology; D013647:Task Performance and Analysis; D014910:Wheelchairs